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tripps 03-22-2025 12:00 PM

741 cam
 
Putting one in a 539 4.125 stroke 4.560 bore cmi cool collar ex single 4 850carb does this cam like advance? Low compression 9 2 1 merc aluminum heads single engine 30 ft boat w pad what is best lifter?

JaniH 03-22-2025 02:26 PM

Have heard only good things about johnsson lifters, so i went with johnsson 2126bbr with axle oling. The engine pulled clean to 6000rpm with heavy valvetrain. My cam is very similar compared to crane 741. Ron sporll 240/245 @050" ,114lsa 108icl.

SB 03-22-2025 06:44 PM


Originally Posted by tripps (Post 4922632)
Putting one in a 539 4.125 stroke 4.560 bore cmi cool collar ex single 4 850carb does this cam like advance? Low compression 9 2 1 merc aluminum heads single engine 30 ft boat w pad what is best lifter?

Crane usually suggested there bbc hyd roller camsvin 5deg from neutral.

other words, the 741 cam has a 112 lsa so get a timing wheel set up and install it so the icl is 107 and ecl is 117.

tripps 03-24-2025 08:24 AM

741
 
Thanks Quit,that was my plan m just checking with my comrades!!!

Brad Christy 03-24-2025 11:06 AM


Originally Posted by quitshore1507 (Post 4922714)
For your 539ci engine with low compression (9.2:1), CMI Cool Collar exhaust, and a single 850 carb, advancing the cam (4-6 degrees) will improve low-end torque and response, which is beneficial for boat performance. For lifters, solid roller lifters are ideal for durability and performance, especially in marine engines, as they handle high RPM and stress better than hydraulic lifters.


Originally Posted by tripps (Post 4922768)
Thanks Quit,that was my plan m just checking with my comrades!!!

Tripps,

Pretty sure this is a bot.

Thanks. Brad.


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